Self-adjusting caster.



H. A. PALMER.

SELF ADJUSTING CASTER.

APPLICATION FILED PEB.12,1914.

1,094,744, Pate nted Apr 28, 1914. I

WITNESSES: lA/l/E/VTOR Z W Br ATTORNEY COLUMBIA PLANOGRAPH CO.,WASHINGTON. D. c,

UNITED STATES PATEN HARRY A. PALMER, OF MERIDE'N, CONNECTICUT, ASSIG-NOR TO FOSTER, MERRIAM AND COMPANY, OF MERIDEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

SELF-ADJUSTING CASTER.

Specification of Letters Patent.

Patented Apr. 28, 1914.

Application filed February 12, 1914:. Serial No. 818,277.

1 '0 all whom it may concern.

Be it known that I, HARRY A. PALMER, a citizen of the United States, residing at Meriden, county of-New Haven, State of Connecticut, have invented an Improvement in Self-Adjusting Casters, of which the following is a specification.

This invention has for its object to pro \ide a caster that will be self-adjusting to different heights within the ordinary limits of use, as, if one or more of the legs of a chair, table or other article of furniture are required to stand upon a rug and the others upon the floor, thus retaining the parallelism of the article of furniture without the necessity of jacking up one or more of the legs by putting wedges under them.

With this and other objects in View I have devised the novel self-adjusting caster which I will now describe, referring to the accompanying drawing forming a part of this specification and using reference characters to indicate the several parts.

Figures 1 and 9- are sectional views illustrating the application of the invention to a pintle caster and showing a changed position of the parts, Fig. 1 showing a raised position of the parts and Fig. 2 a lowered position, as when one or more of the legs of an article of furniture are standing upon the floor while others are standing upon a rug, and Fig. 8 is a view similar to Fig. 1, illustrating the application of the invention to a plate caster and also illustrating a variant form of construction applicable to either plate or pintle casters.

1O denotes the horn of a caster, 11 the wheel and 12 a furniture leg. In the form illustrated in Figs. 1 and 2, a pintle 13 is rigidly secured to the horn and rotates within a socket 1% adapted to be rigidly secured in a furniture leg.

The gist of the invention lies in providing the caster with. a set of anti-friction balls which lie between an upper plate rigidly secured to the socket and a lower plate rigidly secured to the pintle, said plates com prising a ball race, both of said plates inclining outward and upward, the upper plate having the greater angle of inclination. and the lower plate being provided with a plurality of annular ball channels.

15 denotes the lower plate, the general direction of which is an outward and upward incline from the center and which is provided with a plurality of annular ball channels 16 and is rigidly secured to the pintle.

In the present instance I have shown the pintle as provided near its lower 'end with a boss 17 below which is a reduced portion 18 which may be made angular and which passes through corresponding holes in the lower plate and the horn, both of which are rigidly secured to the pintle by a heading, as at 19.

20 denotes the upper plate which is rigidly secured to the socket and extends outward and upward therefrom at a greater inclination to the horizontal plane than plate 1-5, thereby forming between said plates a diverging upwardly and outwardly inclined ball race 21 which receives the balls 38. The outer edge of the upper plate, as at 22, provides the bearing surface upon which the weight rests, and is provided with a clownwardly extending flange 23 which incloses the lower plate and provides a closure for the outer edge of the ball race. As a means of securing the upper plate to the socket, I have shown the socket as provided with a rib 24L of greater diameter than the central hole in the upper plate and against which the inner edge of said plate rests, the plate being rigidly secured to the socket by rolling the lower end of the socket over the inner edge of the plate, as at 25.

In use, where all the legs of the article of furniture are standing upon a level surface, as all upon a rug or all upon the floor, the parts may be either in the position shown in Fig. 1 or in Fig. 2. They will normally, however, assume the position in Fig. 1, and where an article is required to stand partly upon one plane and partly upon a higher plane, the parts should be caused to assume the position shown in Fig. 1, which may be easily eifected by shaking the caster and causing the set of balls, if upon one of the lower ball channels, as in Fig. 2, to ride upward over the ridges between the channels and assume the position shown in Fig. 1, the lower plate sliding upward freely within the flange from the position shown in Fig. 2 or the intermediate position) to the position shown inFig. 1, so that in any position of the parts the lower plate supports the balls, the balls support the upper plate and the upper plate supports the weight. Suppose now, with the parts in the position shown in Fig. 1, that one or more legs of roar tee the article of furniture are moved olf from a. rug, the horn, lower plate and balls will instantly drop from the position shown in Fig. 1 to an intermediate position or to the a position shown in Q, the exact number of ball channels in the lower plate being immaterial tar as the principle of the invention is concerned. li hen the parts are in eituer posi ion, the weight of the article upon the halls and the engagement of the balls with a hall channel will retain them in that position. The article of furniture may be m. vcd about and the caster will operate freely. Should it be required. to shift a caster that has been oil." from a rug upon the rug or make any similar chan c, the parts may be readily caused to assume the position shown in 1 by removing the weight from the caster and shaking it, which will cause the balls to travel up the incline of the lower plate and over the rib or ribs and assume the position shown in Fig. 1, in which the balls not only contact with the upper and lower plates but with the flange '25 which closes the outer edge of the ball race. When the parts are in the position shown. in Fig. '2. in addition to engaging the upper and lower plate the balls will also contact with the boss upon the pintle.

l have illustrated the application of the invention to a plate caster, so called. The upper plate is attached directly to the furniture leg by means of screws passing through an attaching flange 27. The lower plate and the horn are attached to the pintle before. The pintle, however, is relatively short, is adapted to slide vertically in a central hole in the upper plate and lies wholly within the to recess formed by the upper plate and the end of the furniture leg. ln this form, a flange 31. is formed upon the lowe plate which is :ulapted to slide freely over an annular flange :12 formed by folding the metal of the upper plate upon itself, the two flanges serving as a closure for the outer end of the ball race, (a. the space between the upper and lower plates. The operation is precisely the same as before. Having thus described my invention 1 claim 2* 1. A caster of the character described comprising a vertically movable pintle, an iu nvardly and outwardly inclined lower plate carried by the pintle and provided with a plurality of annular superposed hall channels to receive and detachahly hold halls so that they can freely rotate therein, a

fixed upper plate having a greater angle of inclination than the lower plate, whereby a ball race is formed having outwardly diverging walls and a series of balls in said race which normally lie in the upper annular channel, the lower plate andv pintle drop ping down and the balls rolling into a lower channel should the caster pass off from a horizontal support.

2. A caster of the character described comprising an upper fixed plate, a vertically movable pintlc, a lower plate secured to the pintle and provided with horizontal annular hall channels disposed in different horizontal planes, both of said plates being inclined upward and outward and the upper plate having a greater angle of inclination, tor the purpose set fortl'i, and a series of balls in said race.

3. A caster of the character described, comprising an upper conical plate increasing in diameter upwardly, a lower conical plate increasing in diameter upwardly and provided upon its upper surface with annular ball-receiving channels arranged in ditte 'cnt horizontal alanes and increasing in diameter upwardly, balls interposed between the upper and lower plates and adapted to he rotatably and detachably held in each annular channel and removed therefrom by shaking the caster, and means pivotally connecting the upper and lower plates so that they may more vertically toward and. away from each other.

a. A caster of the character described, comprising an upper conical plate increas ing in diameter upwardly, a tubular socket secured to the upper conical plate, a lower conical plate increasing in diameter upwardly and provided upon its upper surface with horizontal annular concentric ballrcceiving channels disposed in superposed relation and increasing in diameter upwardly, balls interposed between the upper and lower plates and adapted to be detachably held in each channel to freely rotate therein and adapted to be removed there from by shaking the caster, a pintle secured to the lower plate and mounted to rotate and reciprocate in the socket, and a wheel connected with the lower plate.

In testimony whereof I atlix my signature in presence of two witnesses.

HARRY A. PALMER.

lVitnesses E. W. IMILLARD, FRANK L. Rooou'rna.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

